sharing problems

My office computer is uses wireless network,but am experiencing problem with sharing.The computer is in the work group,but it seems it is unable to share or see other computers. If I use another computer I can easly access it's shared files but not from that computer.I tried to enable file sharing in my network places and rejoin the work group but when but to no avail. I try to run an IP address(using run on the start menu like:\\123.x.x.x ) of another computer in the work group I can't acces its shared folders.It is prompting for username and password which when given it says it can't find the destination. I can access the server without any problem I can also use remote desktop on the server and the other computers.I am able to view computers in the work group.I tried to use command line and a certain software to switch off another computer it can't find the path.what could be the cause?Please help me

maybe a firewall is blocking file sharing and the other things youre trying to do. ports 135-139 govern what you're after... check the firewall on your computer, the computer youre connecting to, and whatever hardware is in between.

if you are using mac try going to system preferences and choose security then go and click on firewall. Check whether your firewall is on and set to block all incoming connections if yes turn if off. U must be the admin first, click on the lock . type in your username and passowrod then go to advanced to change it

If your firewall is turn off and you still can't screen share with other computer go to system preference again and click on sharing check whether your screen sharing is turn on. if it is turn off but still does not help press shift, command and k. Check if there are any other computer on the same network as you. If yes click on the computer you want to connect and click on share screen. type in the password of the computer you want to share. Both the computers must be on the same ip address in other words the same internet